Dipper-door-tripping mechanism



March 24, 1931.

L. A. RUSSELL DIPPER DOOR TRIPPING MECHANISM Filed April 14 1927 Patented Mar. 24, 1931 LESLIE A. RUSSELL,

OF MILWAUKEE, WISCONSIN, ASSIGNOB TO KOEHRING COMPANY,

OF MILWAUKEE, WISCONSIN, A CORPQRAIIION 'mrrEn-noon-rmrrmo uncnnmsm Application filed April 14,

- As is well known, the usual types of power shovels involve the provision of a boom, a

dipper mounted upon the boom by means of a dipper handle, and means for racking in the dipper and crowding out the same, of some suitable type. The dipper comprises a'door, which when opened, discharges its-contents, and the object of this invention has been to produce a simple operating unit for accomplishing the tripping of the latch means that normally locks said door closed.

The operating unit of this invention, moreover, is not only simply constructed, but is readily adapted to be applied to any type of' power shovel wherein there is employed a constantly operating or rotating member that may be used as the driving element for the mechanism of the latch tripping unit.

A preferred embodiment is illustrated in the accompanying drawings, in which Figure. 1 IS a side elevation of ap'ower.

shovel of known type today, with my invention applied thereto.

Figure 2 is an end view with certain parts broken away showing the driving connection between the constantly driven gear and my tripping unit mechanism.

, Figure 3 is a sectional View taken about on the line 33 of Figure 2.

The power shovel of this invention comprises the usual swing body A, traction base B and operating drum mechanism shown generally at C andincluding a front reversible drum 1 and a rear hoisting drum 2. The drum mechanism C is operated by a gas engine or any suitable motor designated 3, a suitable train of gearing connecting up the engine shaft with the drums 1 and 2 under the control of certain clutches and brakes not shown and not forming a part of this invention. In a diagrammatic way, certain constantly driven gears 4 and 5 are illustrated as associated with the drums 2 and 1 respective: ly. The drum 2 operates the hoisting cable 6 and the drum 1 operates the reversible crowding out and racking in cable means 7.

The swing body A has the boom 8 equipped with the dipper means 9 comprising the dipper handle 10. The dipper 9 has the usual door 11 and door latch actuating means-in- 1927. Serial No. 183,717.

cluding the lever 12 and arm 13. A spring 14 is connected with the arm 13 of the lever 12 and normally holds the lever in a position in which the latch, not shown, is not tripped. Moreover, the tension of the spring 14 is sulficlent normally to prevent tripping of the latch durlng normal slack take-up pull which may be exerted on the trip cable 15. The trlp cable extends from thelever 12 to a trip cable drum 16.

The trip cable 161forms a part of a trip unit D adapted to be mounted upon the swing body A and including a shaft 17 on which the drum 16 is loosely mounted. Keyed to the shaft 17 is a gear 18 adapted to mesh. with the gear 5 previously mentioned and formed with a clutch member' 19 of cone-shape. I Integral with the-drum 16 is a clutch member 20 s1milar in form to and receiving the clutch member 19, suitable friction, means being interposed between the two. The shaft 17 is sup portedm a 'castin or supporting structure 21 of the unit']). 11 order to shift the drum 16 lengthwise of the shaft 17 the structure 21 has mounted thereon a horizontal shifting lever 22 having a vertical shifting yoke 23 engaging a hub portion of the drum 16.

Mounted on a stub. shaft 24 arranged in suitable'bearings on the structure 21 is a control lever 25 having a weight and handle member 26 at its upper end. At its lower end the member 25 has an arm'27 engaging loosely in a loop or eye portion 28 of the shifting lever 22.

With the foregoing construction of my invention in mind, its operation is as follows Normally the control member 25 is inclined at an angle of approximately 20 degrees to the vertical and its weight, plus that of its part 26, is sufiicient to apply an upward pressure on the lever 22 to maintain the clutch member 20 of the drum 16 in slight friction contact with the member 19 of thegear 18. The gear 18 is constantly driven b the gear 5. The normal friction contact t us established between the parts 19 and 20 is sufiic'ient to take up all slack in the trip cable 15. Such frictionaction, however, is not suflicent to exert apull on the latch lever 12 greater than the normal tension of the spring 14.

v and common operating When, however, the operator desires to open the door of the bucket 9, an additional downward movement of the control member 25 will enable sufiicient clutch action between theparts 19 and 20 to positively connect the gear 18 and drum 16 and exert a pullon the cable 15 overcoming the normal tension of the spring 14, and pulling upwardly on the latch lever 12 to unlock the door 11 and permit it to open.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is

1. In combination with a power shovel having a dipper royided with a door, latch mechanism for olding the door closed, a trip cable connected with said latch mechanism, a cable drum about which said trip cable is adapted to wind, a constantly driven member, drive mechanism connected with said drum and acting normally to maintain the said trip cable taut, and including a single control member the normal action of which yieldably connects the constantly driven member with the drum to take up slack in the cable and an abnormal positive movement of which will effect a tripping operation of the said cable.

2. In excavating mechanism of the class described, the combination with dipper door latch mechanism, of instrumentalities for operating the latch mechanism comprising a winding drum, a trip cable on thewinding drum, driving means for causing rotation of the drum, conical clutch instrumentalities between the driving means and the drum, means for normally maintaining the clutc instrumentalities in position to exert slack take up stress on the trip cable, and operable to cause further clutching action of said clutch instrumentalities to impart tripping stresses to the trip cable. a

3. In excavatin mechanism of the class described, the com ination with dipper door latch mechanism, of a trip cable, a drum on which said trip cable is wound, a power driven gear arrangement, clutch means intermediate the gear arrangement and the drum, means for shifting said'drum to cause clutch engaging action of said clutch means includ- -1ng a lever, said lever normally causing clutch action sufiicient to impart slack take up stress to the cable, and operable to cause further clutch action of said clutch means to impart a tripping pull to the cable.

a main winding drum, a gear operatively connected with the main winding drum, conical clutch means intermediate the gear and the winding drum, said winding drum being shiftable to cause clutching action of said means, whereb driving power is imparted to 

